Electric resistance-card



` (No Model.)

A. J. SHAW.

ELECTRIC RESISTANCE CARD.

[TLUQTY/ NMMMMMMMMMUMr Patented Feb. 26, 1895.

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Bf" C UNITED STATES PATENT Greifen,

ALTON J. SHAIV, OF MUSKEGON, MICHIGAN.

ELECTRIC RESiSTANCE-iCARDn SPECIFICATION forming part of Letters PatentNo. 534,699, dated February 26, 1 895.

Application filed December 1,1894. Serial No. 530,588. (No model.)

To tZZ whom t may concern.-

Beit known that I, ALTON J. SHAW, a citizen of the United States,residing at Muskegon, in the county of Muskegon and State of Michigan,have invented certain new and useful Improvements in ElectricResistance- Cards, of which the following is a specification.

My invention consists in a novel construction of electrical resistances,as hereinafter set forth.

The invention is illustrated in the accompanying drawings, in whichyFigure lis a perspective view ofa resistance card, block, or section,embodying my invention, the conducting body being represented in theforrn of a flat strip or band, and a porA tion of the device beingbroken away to better show the construction. Fig. 2 is a similar View,representing the conductor as made of wire; and Figs. 3 and et aredetail views which will be hereinafter referred to.

The invention is designed to produce a simple, cheap and durableresistance device, ca-

pabie of use alone, or as one of a group or series in a rheostat orcurrent regulator.

In the drawings, A indicates a frame which is preferably of cast iron,andcompriscsthree bars a, b and c, the bar b being channeled on itsinner face as shown in Fig.

B indicates a conductingstrip, which is'preferably made of hoop iron orother suitable tlat metallic tape or band folded back and forth uponitself, the several folds or layers being separated one from another bystrips C of micanite or other good insulating material. rPhe ends of thefolds and of the insulating strips C are covered or incased by strips Dof mica, asbestos or other good insulating material, mica beingpreferred because of its good insulating qualities and its proof againstinjury by heat or by electrical action.

The folded band with the interposed strips and with the covering` stripsD applied as` stated and as shown in Figs. l and 2, is inserted withinthe frame A in the manner indicated in Figs. l and 3, the lower strip orsheet D of insulating material fitting within the channel of the bar bof said frame.

rlhe folds of the band b and the interposed strips C are of such lengththat they, together with the upper or second strip or sheet D, come hushwith the uppercnds of the bars a and o of frame A. To retain the foldedstrip and the insulating strips in place, I apply to the open side offrame A a sheet metal cap E, folded as shown in Figs. 3 and e, to form achanneled plate or bar, the sides of which extend downward over theinsulating strip D and over the folded ends of the strip E sufficientlyto retain said partsin proper relation to the frame A.

The upper ends of the bars aand b are provided each with an opening d,and the cap or cover plate E is secured to said arms by forc ing themetal of its side wings or flanges into said openings d by means of apunch or other suitable implement, in the manner indicated in Figs. l, 2and 4:. This affords a cheap and secure fastening and one which may, ifnecessary, be broken or destroyed to permit the removal of cap E.

It will be observed by referring to Fig. l that the first fold of theband B lies in iinmediate contact with the bar d of frame A throughoutits length, so that good electrical contact is established between theframe A and the conductor B at that point, but owing` to the insulationabove described, electrical contact between the frame and the band isprevented at all other points, and consequently if contact be made withthe frame A at. any point, a current can pass by band B only bytraversing its entire length. rlhe other end of band B, that is, the endopposite that which is in contact with bar d, is provided with ametallic tongue or tab e, by which connection may be made with a secondsection or with a line or conductor as desired.

It would of course be possible, if less than the entire resistance ofband B be desired, to make contact therewith at a point between its endsand at one end, but this will not ordinarily be desirable, although forheavy cnrrents when the resistance is low, the tongue or tab c mayadvantageously be attached to IOO in contact therewith, as hereinbeforedescribed of one end only.

The frame A will be provided with suitably tapped holes F to receivescrews or tap bolts by which to fasten the frame A to a suitablesupport.

In Fig. 2 I have represented the conducting band Bin the form of a Wire,one end of which enters a hole in the end bar of frame A, and is madefast therein by a Wedge pin h, by soldering or otherwise. The Wire inthis case is Wound about insulating strips C, similar to those shown anddescribed in connection with Fig. I, similar strips being alsointerposed between those about which the wire is Wound, to prevent foldsof proximate Wound strips from making electrical contact. In all otherrespects the construction is the same as shown and described inconnection with Figs. 1, 3 and 4, that is to say, the same insulatingstrips D and cap or cover plate E are used, and the latter is secured tothe frame A by punching or indenting its side flanges so as to fornieyelets or burrs within the openings e.

In the foregoing description I have relferred to the plate E asconstituting the npper side ofthe frame A, but it is to be understood ofcourse that this expression has reference only to the position in whichthe figures appear in the drawings, it being obvious that any one of thefour sides ot' the frame may be made in the form of the cap or coverplate E. If, as in Figs. l and 2, the end plate instead of the sideshould be made of sheet metal, two paralled sides of frame A would ofcourse be cast With grooves or channels.

In practice it is preferred to make contact or electrical connectionwith the resistance through the frame A, which is ordinarily donethrough one of its end bars, as a in the accompanying drawings; but ifdesired, the conductor may be entirely insulated from the frame and bothits ends brought out in the same manner as the one end in Figs. l and 2.

I do not broadly claim herein a resistance device in which the conductoris formed of a flat metallic band or tape folded back and forth uponitself, nor, broadly, one composed of Wire wound about an insulatingbody.

Having thus described my invention, what I claim isl. A resistancesection, card, or block comprising a channeled open frame A, a coiled orfolded conductor having its folds insulated from one another and mountedwithin said frame, and insulating material interposed between theconductor and the frame, substantially as described and shown.

2. A resistance card or section consisting of a frame A having achanneled bar l), a folded conductor B having its folds insulated onefrom another and inserted within the frame A, insulating strips Dinclosing the ends of the conductor folds, and a removable cap plate Eapplied to the frame and serving to retain the conductor therein.

3. In combination with a frame having openings d, a conductor mountedWithin said frame, and a separate cap plate E applied to said frame andsecured thereto by indenting or forcing the metal of its Hanges into theopenings d'.

it. A resistance card, block, or section, comprising an open frame, aseparate cap or bar applied to said frame and forming one wall thereof,and a conductor mounted Within said frame and held in place by thedetachable cap or bar, substantially as described and shown.

In Witness whereof I hereunto set my hand in the presence of twoWitnesses.

ALTON J. SHAlV.

Witnesses:

F. S. VROOMAN, THos. C. AKIN.

